Complete 14-Bit CCD/CIS Signal Processor AD9822 GENERAL DESCRIPTION FEATURES 14-bit 15 MSPS ADC The AD9822 is a complete analog signal processor for CCD No missing codes guaranteed imaging applications. It features a 3-channel architecture designed 3-channel operation up to 15 MSPS to sample and condition the outputs of trilinear color CCD 1-channel operation up to 12.5 MSPS arrays. Each channel consists of an input clamp, correlated double Correlated double sampling sampler (CDS), offset DAC, and programmable gain amplifier (PGA) multiplexed to a high performance 14-bit ADC. 16 programmable gain 350 mV programmable offset The CDS amplifiers may be disabled for use with sensors such Input clamp circuitry as contact image sensors (CIS) and CMOS active pixel sensors, Internal voltage reference which do not require CDS. Multiplexed byte-wide output (8 + 6 format) 3-wire serial digital interface The 14-bit digital output is multiplexed into an 8-bit output 3 V/5 V digital I/O compatibility word that is accessed using two read cycles. The internal 28-Lead SOIC or SSOP registers are programmed through a 3-wire serial interface and Low power CMOS: 385 mW (typ) provide adjustment of the gain, offset, and operating mode. Power-down mode: <1 mW The AD9822 operates from a single 5 V power supply, APPLICATIONS consumes 385 mW of power typically, and is packaged in a Flatbed document scanners 28-lead SOIC or SSOP. Film scanners Digital color copiers Multifunction peripherals FUNCTIONAL BLOCK DIAGRAM AVDD AVSS CML CAPT CAPB AVDD AVSS DRVDD DRVSS AD9822 VINR CDS PGA OEB BAND GAP 9-BIT REFERENCE DAC 14 8 14-BIT 14:8 3:1 DOUT VING CDS PGA ADC MUX MUX 9-BIT CONFIGURATION DAC REGISTER MUX REGISTER SCLK VINB CDS PGA DIGITAL RED CONTROL SLOAD 66 INTERFACE GREEN 9-BIT GAIN SDATA DAC BLUE REGISTERS INPUT RED 99 CLAMP GREEN OFFSET BIAS OFFSET BLUE REGISTERS CDSCLK1 CDSCLK2 ADCCLK Figure 1. Rev. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Fax: 781.326.8703 2005 Analog Devices, Inc. All rights reserved. 00623-001AD9822 TABLE OF CONTENTS Specifications..................................................................................... 3 1-Channel CDS Mode ............................................................... 12 Analog Specifications................................................................... 3 1-Channel SHA Mode ............................................................... 12 Digital Specifications ................................................................... 4 Internal Register Descriptions.................................................. 13 Timing Specifications .................................................................. 5 Circuit Operation ........................................................................... 15 Absolute Maximum Ratings............................................................ 6 Analog InputsCDS Mode...................................................... 15 Thermal Characteristics .............................................................. 6 External Input Coupling Capacitors........................................ 15 ESD Caution.................................................................................. 6 Analog InputsSHA Mode...................................................... 16 Pin Configuration and Function Descriptions............................. 7 Programmable Gain AmplifierS (PGA) .................................. 16 Terminology ...................................................................................... 8 Applications..................................................................................... 17 Functional Description .................................................................. 12 Circuit and Layout Recommendations ................................... 17 3-Channel CDS Mode................................................................ 12 Outline Dimensions ....................................................................... 18 3-Channel SHA Mode................................................................ 12 Ordering Guide .......................................................................... 18 REVISION HISTORY 2/05Rev. A to Rev. B Changes to Format .............................................................Universal Changes to Ordering Guide .......................................................... 18 Updated Outline Dimensions ....................................................... 18 12/99Rev. 0 to Rev. A Rev. B Page 2 of 20